Long lasting flavor. Accepted by the American Dental Association. The ADA Council on Scientific Affairs' Acceptance of Extra is based on its finding that the physical action of chewing Extra sugar-free gum for 20 minutes after eating, stimulates saliva flow, which helps to prevent cavities by reducing plaque acids and strengthening teeth. 35% fewer calories than sugared gum. Calorie content of this size piece has been reduced from 8 to 5 calories.